.gold-adv {
	height: 500px;
	/* 把gold-adv作为adv-button-box的定位参照物 */
	position: relative;
}

.gold-adv img {
	height: 500px;
	width: 100%;
}

.silver-adv>ul>li {
	float: left;
	width: 25%;
}

.silver-adv>ul>li img {
	width: 100%;
	height: 200px;
}

/* 把三个圆圈圈的位置定在黄金广告区的下方中间 */
.adv-button-box {
	/* 绝对坐标定位 */
	position: absolute;
	bottom: 10px;
	left: 50%;
	margin-left: -34px;
	opacity: 0.5;
}

/* class="adv-button-box"的标签 内部的 span */
.adv-button-box span {
	border: 1px solid #CCCCCC;
	width: 20px;
	height: 20px;
	display: inline-block;
	border-radius: 50%;
	text-align: center;
	background-color: #959595;
	cursor: pointer;
}

.adv-button-box span.active, .adv-button-box span:hover {
	background-color: #FFFFFF;
}

